Evaluation of 25(OH) vitamin D3 and quadriceps strength correlation in postmenopausal women: A cross-sectional study.

Background: Vitamin D deficiency is common in postmenopausal women and is associated with low vitamin D intake, increased age, decreased absorption. Especially at advanced age, vitamin D deficiency may increase muscle weakness and disbalance resulting in increased risk of fracture.

Objectives: This study aims to explore the correlation between 25(OH) vitamin D3 levels and quadriceps muscle strength in postmenopausal women.

Methods: We evaluated bilateral qadriceps muscle strength in postmenopausal women with isokinetic test. We evaluated the correlation of muscle power with measurements of parathormone, vitamin D, Calcium, creatinine, alanine transaminase, alkaline phosphatase, total creatine kinase.

Results: The mean vitamin D level of 95 participants included in the study was 18.24 ± 8.94 ng/ml. Vitamin D levels were found to be deficient (< 10 ng/ml) in 23 (24.1%), insufficient in 62 (65.26%) and normal in 10 (10.53%) of the 95 participants. A weak negative correlation was observed between participants' vitamin D levels and PT values (r=-0.271, p= 0.012). A moderate negative correlation was found between ALP and vitamin D levels (r=-0.317, p= 0.002). However, there was no significant correlation between vitamin D levels and the 60∘ and 90∘ flexion and extension peak torque values (All p values > 0.05).

Conclusions: Vitamin D levels and muscle strength weren't statistically significant. Few studies are available in the related literature, highlighting the need for further research to achieve a clearer consensus.